Arm · Workspaces · Core
Span
The distance from fingertip to fingertip with arms extended.
Span
How to measure
Application
Used in ergonomic reach envelope modelling, sports science performance assessment, and as a clinical proxy for stature in patients unable to stand. Span is closely correlated with stature in healthy adults.
Posture
Stand upright, arms extended horizontally at shoulder height, fully outstretched to the sides.
Landmark
Measured from the tip of the middle finger on one hand to the tip of the middle finger on the other.
Tool
Tape measure along a marked wall.
Assistance
A second person is required to hold the tape end and confirm both arms are level.
Common mistake
Dropping the arms below shoulder height reduces the span. Keep both arms fully level throughout.
API example
Request a predicted value for a 34-year-old woman at the 50th percentile in the United States. Adjust age, percentile, gender, and country to match your design scenario.
POST https://api.humanform.app/v1/predict
Authorization: Bearer hf_live_...
Content-Type: application/json
{
"measurement": "Span",
"gender": "Female",
"age": 34,
"percentile": 50,
"country": "US",
"unit": "cm"
}Response values depend on age, percentile, gender, and country. Create a free dashboard account to run live predictions.
See design examples for worked scenarios that combine multiple measurements, or read the methodology page for percentile-based design thinking.
Explore the dataset
Humanform covers 148 measurements with country-adjusted predictions and separate female and male profiles. Browse the full inventory or read the API reference for request syntax.